Why interrupt our president for this bit of stuffy financial news? Why was it met with roaring cheers from hundreds of students from unions across the country? Because it proved that our divestment campaign was working. We were making change happen.

Throughout the 1970s and 80s, divestment was a decisive tactic in the NUS campaign against apartheid in South Africa, particularly targeting Barclays Bank. Tens of thousands of students closed their accounts, shrinking that market share by 10% in just two years, while dozens of students’ unions across the country campaigned relentlessly for systemic divestment.

One of the biggies is that divestment won’t bankrupt the fossil fuel companies: our investments are just a drop in the ocean; someone else will buy the stock. Well, that’s all true enough. But that’s not the point, and it wasn’t the point when we did it 30 years ago either. Nobody thought we’d end apartheid by bankrupting the regime. It was about delegitimising them, shifting public opinion, and ramping up political pressure.

The student movement made a massive contribution to the collapse of apartheid, and did so by undermining the system politically as well as financially. But make no mistake: although the main aims were political, a $350m hit is real financial pressure too. Divestment is a long-term game. We could bankrupt them.

Another objection is that universities shouldn’t politicise their investments. They should make use of all money and funding, some argue, solely to become the best institutions of education they can possibly be. That sounds good to me too. But a huge part of that is ensuring that our education system contributes to a truly sustainable society and economy – and that means not funding climate change.

It’s difficult to picture an organisation like the British Medical Association making a similar argument about why they should have their money in, say, tobacco companies. “We don’t want to politicise our investments! We’re just interested in doing everything we can to promote public health!” Obviously, that makes zero sense. And that’s why loads of health organisations led a movement for tobacco divestment just a couple of decades ago.

You can’t be preparing 7 million students for the future on one hand, while undermining every chance of a decent future

Institutions that keep trying to make these moth-eaten arguments are sounding feebler by the day. You can’t be preparing 7 million students for the future, while undermining every chance of a decent future. It defies common sense.

I’m thrilled by all the institutions who have already pulled their money out of fossil fuels, and by the tens of thousands of staff and students calling for divestment across the UK. If you haven’t already, get in contact with your students’ union to join your campus’s campaign right now. We know half of students want it already, and that momentum is building.

I’m proud to be part of a movement that is still on the right side of history in our most crucial fights for global justice, just as we were in the 1970s and 80s. Sometimes you act on principle simply because it’s the right thing to do. Sometimes, you act pragmatically to make a real impact. Divestment does both these things at the same time, and it’s as effective now as it was during apartheid.